On Fri, 2015-07-24 at 12:15 -0700, Kent Overstreet wrote: > On Tue, Jul 21, 2015 at 10:11:11PM -0700, Ming Lin wrote: > > On Fri, Jul 17, 2015 at 10:21 PM, Ming Lin <mlin@xxxxxxxxxx> wrote: > > > On Fri, 2015-07-17 at 19:10 -0700, Kent Overstreet wrote: > > >> BTW - probably the most valuable thing you could help out with is the > > >> documentation, in particular the guide: > > >> http://bcache.evilpiepirate.org/BcacheGuide/ > > >> > > >> Can you read through (at least some of) that, and tell me what's useful and what > > >> needs clarifying? And tell me what you'd like to see added to the guide next - > > >> I'll try and work on documentation over the next two weeks, since I probably > > >> won't be able to do much real coding with my test machines offline. > > > > > > Yes, I'll read through that. > > > > Would you add some example to explain how the extents/inodes/dirents are stored > > in the btree on disk? > > Can you be more specific? Like how inodes/dirents map to keys in the btree, or > how it all ends up on disk? How it all ends up on disk. > > The inodes/dirents code is pretty short, I'd look at inode.c and dirent.c > > > I'm reading the debug code in drivers/md/bcache/debug.c. > > It seems helpful to learn about the internal btree structure. > > Are you interested in more the format of the btree node itself, on disk? Like > struct btree_node, struct btree_node_entry, struct bset, and the packing? > > I could try and elaborate on that in the guide, give me some specific questions > to cover if you've got any Only textbook knowledge of b+tree. Yes, I'm interested in the format of btree on disk. Some graph like this could help. https://btrfs.wiki.kernel.org/index.php/Btrfs_design And I want to learn how the btree node insert/delete/update happens on disk. These maybe too detail. I'm going to write a small tool to dump the file system. Then I could understand better the on disk btree format. Thanks. -- To unsubscribe from this list: send the line "unsubscribe linux-bcache" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
